Hydraulic pump or motor



July 8, 1941.

E. K. BENEDEK HYDRAULIC PUMP OR MOTOR Original Filed Nair: 20, 19:55

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1-: K. BENEDEK HYDRAULIC Original Filed NOV. 20, 1935' PUMP on MOTOR 5 Sheets-Sheet 2 rfiram :F flea K 65415-0544.

July 8, 1941. E. K. BENEDE IK HYDRAULIC PUMP OR MOTOR Original Filed Nov. 20, 19:55

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HYDRAULIC PUMP OR MOTOR I Original File d Nov. 20, 19:5 5 Sheets-Sheet 4 July 8, 1941. E. K. BENEDEK HYDRAULIC PUMP 0R MOTOR Original Filed Nov. 20, 1935 5 Sheets-Sheet 5 XII 6/ Patented July 8, 1941 UNITED STATES". PATENT OFFICE iiifififiiiiifif Original application November 20, 1935, Serial Divided and this application November 20, 1939, Serial No. some:

suit without a sacrifice in strength of the reciprocating parts.

Another object is to reduce the number of parts necessary for the connection between the piston and reactance to a minimum.

Another and more general object is to provide for anti-friction driving transmission between the barrel and the reactance in. a manner such that high efllciency can be provided at high commercial pressures and speed and accurate synchronization of the speeds of the rotors can be maintained under all conditions of operation.

Other objects and advantages will become apparent from the following specification wherein reference is made to the drawings in which:

Figure 1 is a longitudinal sectional view of a pump or motor embodying the principles the present invention;

Figure 2 is across sectional view taken on the "plane indicated by the line 2--2 in Figure 1;

Figure 5 is a longitudinal cross sectional view I of part of a modified form of pump or motor structure and is taken on a plane indicatedby the line 55 of Figure 6;

liar to Figure 2 illustrating a modified piston head and reactance combination;

Figure 12 is a cross sectional view taken on a plane indicated by the line 12-42 in Figure 11; Figure 13-is a sectional view taken on the plane indicated by the line ll-l8 in Figure 12;

Figure 14 isa fragmentary view oi the reactance ring shown in Figure 13 illustrating certain operating characteristics and relations of the ring I the cross pins oi the present invention, and illustrate also operating characteristics of other needie bearings shown herein.

This application is a division of my applica- I tion Serial No. 50,671, filed November 20, 1935, upon which Patent No. 2,180,343 was granted on November 21, 1939.

Referring first to Figures 1 to 4 inclusive, the present invention is shown embodied in a pumping structure wherein a rotary reactance is employed, its use in connection with pumps and motors of the oscillating type being apparent thererrom. The pump includes a rigid housing or casing 1, which serves as a frame and in which is mounted a valve pintle 2, the valve pintie having reversible valve ports 3 and 4 ior valving cooperation with the cylinders, as.- dacribed below. The ports 3 and 4 are connected by suitable pairs of ducts I and 8 respectively, with diametrically opposite main ports 1 and 8 respectively nected through suitable ducts, not shown, formed Figure 6 is a cross sectional view taken on a I plane indicated by the line 6-8 of Figure 5;

Figure '7 is an elevation 01' one of the pistons and associated head shown in Figure 6 Figure 8 is a fragmentary plan view oi a portion of the barrel and associated piston shown in Figure 6, as viewed :irom the plane indicated bytheline88 oiFigureS; I

Figure 9 is a cross sectional view taken on a plane indicated by the line 9-9 in Figure 1 and illustrates the barrel mounting thereof as well as the mounting of the barrel shown in Figure 5; Figure 10 is an elevation of one 01' the cross pins utilized in the structure shown in Figure 5;

Figure 11 is a fragmentary sectional view simin the housing I with an external fluid circuit.

A cylinder barrel it having an axial bore Ila is rotatably mounted in the casing on heavy duty full complement ball bearings Ii, arranged one set at each end of the barrel and securing the barrel in fixed axial and radial position within the housing. Positive but slight radial clearance between the barrel bore and pintle 2 is maintained by sets of elonlsatedi'ree rollers i2 and i3 respectively, arranged one set at each end oi the plntle and operating on raceways formed directly on the plntle.

The barrel has a plurality of radial cylinders 15, each having a cylinder port ii for cooperation successively with the ports 3 and I as the barrel rotates. Mounted one in each cylinder are pistons i'l, each having an enlarged head It elongated lore and all: from the axis oi the as central portion and reduced end portionsfla.

The reduced end portions Ila of each pin are mounted on capillary cageless rollers in aligned bores of the rings I. and extend beyond the outer radial faces of the rings II. The ends of the pins are recessed to receive snap washers 22 which engage the outer radial faces of the rings and constrain them from axial operation. The larger central portions of the pins 2i provide radial shoulders for retaining the capillary rollers in the respective bores and for maintaining the rings in proper axially spaced relation by rolling I engagement therewith.

Each head it has an arcuate slot or operating way l8a which accommodates the enlarged central portion of the associated pin 2| and is in rolling engagement therewith, slight operatin clearance being provided. The operating ways are segments of circles concentric with the rings IS. The axis of the pin ii is parallel with the axis of rotation of the barrel and rings II and normal to the longitudinal axis of the head. The central portion of the pin ii is of such diameter relative to the piston that the radial hydraulic piston load will be applied within the projected area of the piston in the arcuate way of the head so that there isa. rigid, non-yielding load application between the piston and pin. The tangential rolling reciprocation of the pin in the way I80 will not be more than the diameter of the piston and as a result of this manner of applying the load, a very light crosshead structure can be utilized so that the inertia of the high speed rotation and reciprocation is reduced. For this same reason, the pistons may be made of duraluminum.

Another very important feature is the simplified movement and relation between the cylinder barrel and the reactance rotor rings. The

pistons and heads are preferably made of a single piece of material forged to the proper shape. Due to the fact that the rolling pins 2| are mounted anti-frictionally in the rings ii,

the resistance to rotation thereof in the rings is less than the rolling frictional engagement of the pins with the operating surfaces of the ways a as a result of which anti-friction rolling cooperation is provided and binding and sliding of the pins in the ways are eliminated.

The cylinder barrel II is connected to a drive shaft 23 which it drives when the device is functioning as a motor and by which it is driven when the device is functioning as a pump. Relative movement between thepiston l'l and'the cylinder ii is secured by placing the stator 2.

in an eccentric position with respect to thepintle 2 and the cylinder barrel ll. Control rods 24 secured to the stator 2| and projecting out through the ends of the casing vl are provided for this pu p se.

Referring to Figures to inclusive, there is illustrated a barrel ll having a radial flange 3i and radial cylinders 32 in the zone of the flange. The reactance comprises a stator 33 which rotatably supports axially spaced reactaaaavss ance rings 34. Mounted in each cylinder is a piston 35 having a crosshead I which is accommodated between the rings N with operating clearance only. The flange 3| has a plurality of radial guideways 31 aligned with the cylinders respectively, the guldeways having cylindrical endwalls snugly engaging complementary end walls of the heads 38 so as to preventlateral rocking of the heads and for transmitting torque.

Eachhead 38 has an arcuate slot or way "a corresponding to the way Ila of the structure of Figure 10. Correspondingly cross pins II having relatively large central portions 38a and reduced end portions Ilb are mounted in the reactance rings 34 by the reduced end portions.

Here again, due to the anti-friction mounting of the ends 38b of the pins 38 in the rings 34, rolling cooperation only between the central portion lla of the pins and the ways 36a. is provided.

. In this construction there is combined the load application to the piston along a circular path and a piston cross head which is fixed in relation to the piston, whereas heretofore piston structures in which the load is applied along an arcuate path employed the pistons which were separated from the heads so as to provide for self-adjustment. This structure is made possible by the cooperation of the head and guldeways 31. When the piston and head are separated, as in prior structures, there is a rocking movement with respect to the cross pin and the piston so that the crosshead describes a semi-crank motion which imposes a substantial destructive tangential component of load on the piston through the cross pin, and upon the cylinder walls. In the present structure, however, since the load is well guided and supported by the guideways 31, and unnecessary heavy reciprocating parts are eliminated by mounting the pins in the reactance rings instead of directly in the head, this rocking action is reduced or eliminated and is preventedfrom reaching the pistons in a degree suflicient to cause wear and binding. The ways Ila necessarily lighten the reciprocating head so that high speed and high pressures as may be necessary may be used. In all the forms of the invention hereinbefore illustrated, the axes of the rolling pins and the operating ways are disposed at the normal neutral axis of the associated heads. 1

Another form of the invention is illustrated in Figures 11 to 14 inclusive, this form of the invention being provided with pistons with crossheads having separate load transmitting and torque transmitting rolling pins. In this structure, a barrel ll having radial cylinders ii is provided, each cylinder II carrying a radial pis ton 52 having a head 58 corresponding in shape generally to the head ll heretofore described. The head I! is also tapered from the mid portion toward the ends so as to provide as near as may be a constant strength beam.

Rotatably mounted in the head H with its axis intersecting the piston axis is a load transmitting rolling pin N having reduced diameter I end portions 54a. The pin is mounted in the 2,24s,7as

head 53 on capillary cageless needle rollers 55. In advance of and to the rear of the pin 54 and equidistant from the axis thereof are torque transmitting rolling pins 56 each having reduced diameter end portions 56a. The pins 55 are also mounted on capillary cageless needle rollers 51 in the head 53. The rollers 58 are disposed with their axes in a plane through the axis of the roller 54 and normal to the piston axis. The rolling pin 54 acts as rolling load transmitting means and since each pin carries the direct thrust of the associated piston substantially in the line of the piston axis, each pin 54 acts as means for reinforcing the associated piston head substantially in the zone of the piston axis. Rotary'reactance rings 58 are provided for coaction with the piston heads and pins and lie alongside the opposite faces of the heads, the rings being secured together by suitable bolts 59, the accurate axial spacing of the rings 58 being maintained by spacers 60. The rings, in turn, are rotatably mounted in a stator 6| which opcrates in the usual manner. The rings 58 have axially aligned chordal ways, each way comprising a radially wide portion 58a for rolling and oscillating coaction with the ends Sta of the load pin 56, and symmetrical end portions 581! of less radial dimension, the end portions coacting with ends 56a of the torque transmitting rolling pins 56.

The specific operation of this structure is best illustrated in Figure 14.- Assuming the barrel to be driven in a clockwise direction, it is apparent that the hydraulic load will be taken by the pin 54 which, though oscillating along its slots 58a, applies the load within the projected area of the piston. In efiecting the torque transmission, there is a very slight rocking of the head which causes engagement of the leading roller 56 with the radially inward operating surfaces of the ways 58b, and the trailing rollers 56 with the outer operating surfaces of the associated ways 58b, thus providing positive torque transmission. Necessarily any such rocking is about the axis of the pin 54, as illustrated by the various positions of the lines X1 and X: in Figure 14, the line X1 representing the plane of the axes of the pins 56 and the line X: representing the axis of the piston 52. However, irespective of such rocking, the plane Xi of the axes oi the pins 56 is perpendicular to the axis X: of the piston at all times.

In Figure 14, the actual clearance between the ends 5641 and cooperating surfaces of the ways 50b is greatly exaggerated for purposes of cleamess in illustration. The actual clearance is such that if the radial clearance for the pin thrust or load pin 54 is given, the clearance for the pins 58 would be very slightly more so as to assure thatthe load will be primarily applied by the pin 54 and not by the pins 56.

Obviously, in such a structure, excessive wear would affect the operationand consequently all surfaces are made or non-wearing material such "as nitralloy or the equivalent. Preferably nitralloy pins having a surface hardness of, 1000 Brinell and reactance rings having corresponding hardness are used, as the wear in such instance is not sufficient to appreciably afiect the operation.

A simpler form of the invention just described isillustrated in Figure 15. In this form of the invention, the crosspins are rotatably mounted in the head of the piston with the operating ways in the reactance. For example, in Figure each piston 65 has a crosshead 88 with the major axis of its cross section parallel to the piston axis. Rolling thrust pins 61 are mounted on capillary rollers 55 in the head 66, the axis of the rollers 68 lying in a plane normal to the vpiston axis. The two thrust pins 61 are similar to the thrust pins 55 in the'form of the invention illustrated in Figures 11 to 14 and cooperate with chordal ways in reactance rings lying at either side of the'piston head 66, the chordal ways being of uniform width and the remainder of the structure being similar to that illustrated in Figures 11 to 14.

Referringto Figures 16 and 17, .an unusual operating phenomenon results from the use of capillary rollers mounted as shown between two members X and Y which are relatively rotatable, one such member being a reactance ring or piston head, and the other being a thrust pin. The capillary cageless rollers are disposed between the members X and Y with a total circumferential clearance equal from slightly less than 1 to about 2 needles. For example, the needles may be packed between the members X and Y and then one or two needles of the full complement removed. The needles operate in an oil bath, which, in the present pump, is provided by slip fluid. Assuming the load to be applied to the member X, in the direction of the arrows Z1 and Z: in Figures 16 and 1'? respectively, an unexpected reaction occurs. It is found that the needles crowd to the loaded zone instead of being driven away or squeezed out from under the load. The needles opposite the loaded zonecorrespondingly separate circumferentially'as indicated by the Upon the separating of the needles, as indicated by the arrows s, the resultant clearance space between the unloaded needles sucks in oil. Obviously in a reciprocating member wherein the load is first applied in one direction as indicated in Figure 16 and then in the opposite direction as indicated in Figure 17, full complement bearing for load is provided with a separation of the needles at the unloaded side for receiving oil. Upon reversal of the operation, as

upon the suction stroke, the opposite side becomes loaded and the needles rush to the said opposite side, again assuming the load and separating the first, and now unloaded side, again replenishing the oil. Thus each needle of the set may rotate freely about its own axis unconstrained by adjacent needles and remain in rolling engagement with both races due to capillary oil flIms and full rolling bearing surface at the instantaneous loaded side is provided.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:'

1. In a rotary radial piston pump or motor, a rotatable barrel having radial cylinders therein, valve means for the cylinders, pistons. in the cylinders respectively, heads on and rigid with.

- operating way concave toward the axis of ro-'- tation, rollers rotatably mounted at their ends in the said wall portions and having portions in load transmitting rolling engagement with the operating ways of the heads respectively, said last mentioned roller portions being of such diameter relative to the eccentricity and diameter of the piston as to have its axis always within the projected piston area.

3. In a rotary radial piston pump or motor, a rotatable barrel having a plurality of radial cylinders, valve means for the cylinders and a rotary reactance in eccentric relation to the barrel and surrounding the same, radial guide means on the barrel, heads on the pistons reciprocable in and guided by said 'guideways, arcuate operating ways in the heads, load transmitting rollers rotatably mounted at the ends in said reactance means and in rolling engagement with the operating surface of said ways.

4. In a radial piston pump or motor, a plurality of radial cylinders, valve means for the cylinders. pistons in the cylinders respectively, heads on the pistons, a rotary support having radial walls lying alongside the heads of the pistons, load transmitting rollers antifrictionally mounted at the ends in the radial walls and extending parallel to the axis of rotation of the support, v arcuate operating ways extending through said heads and having their radius of curvature coincident with the axes of the associated pistons and being concentric with the support,and engaging the central portions of said pins for rolling coaction therewith.

5. In a hydraulic machine of the class described including radial pistons, a rotary support having radial portions lying alongside the plane of the pistons, and connecting means extending parallel to the axis of rotation of the pistons and carried by said rotary support, rigid heads on the piston and lying between said radial portions of said rotary support, said heads having arcuate slots embracing said connecting means.

6. In a hydraulic machine of the class described including radial pistons, a rotary support having radial portions lying alongside the plane of the pistons, and connecting means extending parallel to the axis oi rotation of the pistons and carried by said rotary support, rigid heads on the piston and lying between said radial portions of said rotary support, said heads having arcuate slots substantially concentric with said rotary support and embracing said connecting means.

7. In a hydraulic machine of the class described including a rotary block with radial cylinders, radial pistons in the cylinders, a segmental piston head supporting ilange on said block having segmentsprojecting radially between said cylinders, a rotary support having radial portions lying alongside said segments, and connecting means extending parallel to the axis of rotation of said block and carried by said rotary support, rigid heads on said pistons, said heads fitting slidably between said supporting flange segments and having arcuate slots embracing Said connecting means.

ELEK K. BENEDEK. 

